Angiopoietin (Ang),as a cytokine found in recent years that can promote angiogenesis,belongs to a growth factor family including Ang 1,Ang 2,Ang 3 and Ang 4.Most research focus on Ang 1 and its receptor Tie 2.Different from vascular endothelial growth factor,Ang 1/Tie 2 affect the end of angiogenesis,induce cell migration and maintain survive of endothelial cell and play an important role in angiogenesis and maintenance of the stability of the neoformative capillary network.Ang 1 is composed of 498 amino acids.The homology between human and mouse is 96.7%.Ang 1 is extensively distributed in tissues containing rich blood vessels such as muscle,prostate,ovary,uterus,but little is in tissues which have no or a few blood vessel.Adenovirus vector is able to transfect effectively Ang 1 gene to MSC.Previous studies have demonstrated that MSCAng 1 cell can highly express and secrete Ang 1 protein.MSCAng 1 could survive in the cardiac muscle tissue of acute myocardial infarction rat,and express exogenous Ang 1 protein for a period time.In acute myocardial infarction,MSCAng 1 cell have more potent effect on prompting angiogenesis than MSC cell.Moreover,MSCAng 1 cell could further reduce infarct size,increase thickness of cardiac ventricle wall,and improve cardiac muscle reconstitution.This study aim to find differential expressed protein related with Ang 1 using proteomic technologies.Protein spots showing significant difference by gel image analysis and statistics analysis were selected for identification using ESI MS/MS.We hope this work can provide new clues for the study on mechanism of action of Ang 1.